John taggart



JOHN TAGGART, OF ROXBURY, ASSIGNOR TO HlMSE-LE' yAND JEROME A. BACON, OE. BEDFORD, MASSACHUSETTS.

I Letters Patent No. 76,270, dated Merch 31, 1868.

IMPROYED MACHINE POR MAKING BAPER-PULP.v

TO ALL PERSONS lO WHOM THESE PRESENTS MAY COME:

Be it known that I, JOH TAGGART, of Roxbury, in the county of Norfolk, and State of Massachusetts` have invented a new and useful Machine for Reducing Rags or other Fibrous Material to Pulp for-being made into Paper; and I do hereby declare the same to be fully described in the following` speeiiicntion, and .represented 'ih the accompanying drawings, of which- Figure l s a top view, and

Figure 2 a transverse section of the reducing-mechanism, and the vat or tub containing it.

In such drawings, A denotes a vat or tub, which maybe square in shape, or of other proper form. In or nearone corner of thc tub, or in any other proper part thereof, I arrange a hollow conicifrustuln, B, having its lesser' base or bottom elevated a short distance above the bottom of the tub. Tithin the said hollow conic frustum .B is a conic frnsturn, C, flxed co'ncentrically upon a vertical shaft, D. The lower end of the shaft, or the frusitum C. thereof,is stepped or supported in a lever, E, whose free end is sustained by a rod, F. This rod has a sereine, and a nut, c, arranged on it, and goes through a stationary ear, a, projecting from the tub, the whole being as exhibited in g. 2. The shaft I support in a bearing, d, the upper part, c, of the shaft beingprisrnatim and going through a bevel-pin ion,.G. Such pinion is supported on the said bearing, and engages with a drivingvbevebgear, ILaxed to a shaft, I, which, when the machine is in use, maybe revolved by any suitable motor. The prismatic part, e, 0f the shaft should slide freely in a correspondingly-shaped eye, 7', made 'in the pinion, and should extend below such eye, in order that the shaft may rise or move vertically through the pinion when any foreign substance, such as a nail or a button, for instance, may he caught between the cutting-threads ofthereducing-frusta. The outer curved surface of the male or inner frustum C has a helical thread. f, running around it, from top to bottom of it, such thread being either square, rectangular, or trapei, zoidal in its transverse section, the said thread being as shown in Figure 3, which is a side elevation of the said frustum The outer or female frustui'n B has another such helical thread, f, arranged on its inner surface, i and extending from the bottom to the top thereof, such being as represented in Figure 4, which is a vertical section of the frustum B. The thread of one frustum, howevenis pitched or inclined in a direction opposite to that of the other, so that when the edges of the threads are brought together, or in close proximity, and the i inner frustuin is in revolution within theA outer one, such threads shall operate to shear and reduce rags or i paperfstock when introduced between the two frusta. Instead of screw or .helical threads formed ou and extending around the curved surfaces of the two frusta inma-uncr as specified, helical grooves made in such surfaces, and so arranged, maybe substituted, one of such grooves being pitched in a direction opposite to that of the other. This inode of making, the frusta, I do not, however, deem so advantageous as that hereinbefore By revolving the inner frustumin one direction, when the tub is supplicdjvith water, so as to extendaabovc the top of the outer frustum, a powerful current of the water will be induced downward between the frusta, but when the inner frustum is` revolved in the opposite direction, a powerful current of water will be caused to ilow upward between the frusta. i Y

"ihe upper part of the thread of each or either fiustum may be serrated or cut into teeth, as shown at hin figs. l and 3. This will enable the frusta to catch the bunches or masses of rags, or fibrous material, and tear the same in pieces before they may further pass between the helical cuttingthreads of the frusta. rlhe two frusta thus made may be termed conical shears, as they operate to cut the rags or paper-stock, and eifect the reduction of such to pulp with very great rapidity.

Each of the frusta will operate like a. screw-propeller, to force the liquid and paper-stock between the pair of frusta, and, in consequence of this, a very quick current of the liquid, and a vast' amount of reduction of the stock, will take place in a very short time.. The rapid reduction of Ithe stock, or the formation of paperpulp, by this machine, in comparison to ordinary pulpgriuders in use, is very remarkable. t The tub or cistcrn may bc cylindrical in forrn,and have the frusta arranged conccntrically within it. Instead of the conic frusta, two cylinders vmay be employed, one oi' such cylinders heing'placcd conceutrically within the other, screw or helical threads being formed on theinner surface of' the outer, and the outer surface of the inner of the two, and arranged with opposite pitches. The disadvantage of this form of-my invention, however` is that the opposing helical threads-will soon become worn, while in'use, to such extent as to render the machiueoi` little value, whereas, with the conic frusta, we have only lto raise or lower in the inner frustum in order to either increase or diminish the space between the opposing threads, or we may bring the opposing threads incontact, and grind'theln together by means of crnery, -or other proper material, introduced between them while the inner frustum may be in revolution. l

l I am aware that two conic frusta, one being arranged Within the other, and both being provided with teeth arranged in their next adjacent surfaces, have been used as a means of reducing and grinding grain, bones, plaster, and various other substances. I am aware that such have been' employed in the reduction of paperstock to pulp. The'd'istinguishing difference between such machines and mine is that I do not use teeth alone, or straight cutters, on the surfaces ofthe frusta, but employ continuous spiral or helical threads, going around A the frusta, and so arranged that the pitch of the thread of one frustum shall be in a direction'opposite to that of the thread'of the other frustum. In this way the helical grooves or spaces formed by the threads of thetwo frusta .constitute channels for the owage of. the liquid -and materialto be reduced, though the outer frustunl and the threads operate as screw-'propellers to force the liquid through the said outer frustum, the threads in the meanwhile operating as'continuous rotary shears, to eifect the reduction of the stock.

What, therefore, I claim as my invention is--'y The combination of. the maleand female cylinders or frusta, and the helical threads thereof', arranged on them so that that or those of one cylinder or frustum shall be pitched in a direction opposite to that or those Aof thev other, as specified, the sume being for use iuv manner andfor the p urpose substantially-as hereinbefore set forth.

I also claim the reducing-cylinders or frusta, made with helical threads, arranged with opposite pitches, as described, and as having teeth formed on the upper part ofeither or each cylinder or frustum,v as set-forth,

I also claimthe application of the shaft of the inner -of the twofrusta, madeas described, to the drivingpinion and bearing of such shaft as to enable the' frustum to rise within its fellow under-'circumstances substantially as set forth, 5

And, in combination with the reducing-frusta, so made with helical threads, arranged to pitch in opposite directions, as set forth, I claim means, substantially as described, .or its equivalent, for supporting the inner frustum, and adjusting it in altitude, as specified. l

I also claim the arrangement or combination of the two frusta, made, asl described, with a tank or'tub, substantially in manner as set forthfwhereby the contents reduced in a'liquidpwhen in the tiib, and the inner frustuin may be in revolution, are made to flow radially and vertically with respect to the outer frustum, as specified, such causing thepul-p, in passing into the reducing-frustum, to convergejtoward a common centre, and, .in passing cnt of such frustum, to diverge from the frustum tangentially, or thereabouts, whereby the pulp will be mixed to great advantage. v ,Y

'i JOHN T AGGART.

Witnesses ;R. H. EDDY,

F. P; HALE, Jr. 

